Many truck trailers, particularly those hauling loose loads such as sand and gravel, need a cover to prevent the wind from blowing load particles off the load bed. Various apparatus have been devised for covering a trailer load. Some such apparatus include a motor for selectively winding a flexible cover. An effective cover should be one which is easily operated by the truck driver so as to selectively cover and uncover the load from the convenient location of the truck cab. My U.S. Pat. No. 5,031,955, the disclosure of which is hereby incorporated by reference, provides a truck cover which may be conveniently motor operated from the cab of a truck to extend the cover from a winding assembly proximate the front of the truck bed and toward the rear of the truck bed.
A need also exists for systems that cover the trailer from side to side. For instance, U.S. Pat. No. 5,328,228 shows a cover for truck bed and cargo. Similarly, U.S. Pat. No. 5,924,758 shows a roll assist mechanism for tarp systems. My U.S. Pat. Nos. 6,206,449 and 6,527,331, the disclosures of which are also hereby incorporated by reference, show a side-to-side truck cover system including a pair of arms, each of which includes a base and an extension.